An adhesively bonded asymmetric weak zone was proposed as a model for studying the problem of interaction between crack-like defects in an elastic medium. The opening of the weak zone was prescribed by a two-parameter basis function, i.e. by a special dislocation which automatically accounts for the asymmetry and other expected physical features of the stress–strain field near the tips of the weak zone. The adhesive forces corresponding to the prescribed opening were then calculated from the solution of the particular problem. The application of the model was demonstrated on the problem of a long interface crack subjected to wedge opening forces which was separated from a short co-linear interface weak zone by a small unbroken strong microstructural feature (a small obstacle). Two key questions pertaining to limiting situations were addressed: firstly, when does the weak zone become the nucleus of a cohesive crack in its own without linking with the pre-existing long crack. Secondly, when does it force the rupture of the obstacle and coalesce with the long crack.

Dislocation Model of an Asymmetric Weak Zone for Problems of Interaction Between Crack-Like Defects. I.V.Simonov, B.L.Karihaloo: Philosophical Magazine, 2005, 85[17], 1847-64